The Yankee Fork River, historically a major Chinook salmon producer, has been severely altered by dredge-mining that occurred between 1938 and 1952, eliminating much of the natural meander pattern of the stream and associated in-stream habitat, riparian vegetation, and function. The restoration and monitoring work contracted under project 2002-059-00 is implemented with the goal of restoring natural river channel characteristics, floodplain function, hydraulic and sediment regimes, and aquatic habitat within the dredged reach of the Yankee Fork Salmon River (YFSR). The Yankee Fork Restoration Project has focused on restoring an approximately six mile section of stream habitat on private land in the Yankee Fork basin by removing or redistributing dredge tailings piles to restore or improve the connectivity of aquatic and floodplain habitat; by the addition of large woody debris, boulders, substrate, and riparian plantings to improve the complexity of aquatic and riparian habitat; and by creating or rehabilitating existing side channels.  Restoration work has been completed with goals of increasing the amount of aquatic habitat available and suitable for fish at all life stages, while at the same time reducing velocities to encourage sediment deposition for the continued improvement and maintenance of channel morphological complexity and floodplain soil conditions.  

The Yankee Fork Restoration Project has been collecting data since 2006, including juvenile abundance and distribution (via snorkel surveys) at restoration sites and unrestored sites in the basin. In 2020 topographic habitat surveys were conducted to monitor changes in habitat at the Bonanza site. These data can be compared to data at a later date to assist in determining any significant changes with large wood mobilization, depth of pools and number of pools, sediment deposition/aggregation, and changes to other habitat features.  Staff will collaborate with other Yankee Fork ID team members (e.g., Trout Unlimited, U.S. Forest Service) to assess fish presence, habitat use, and movement, as well as assessing stream flows and groundwater dynamics through the Bonanza reach.  Data collected for these surveys will include discharge measurements and photo points. The project will also enter data collected from past years into a database and the Yankee Fork ArcGIS platform.

The Bonanza City project is at the upstream end of the dredged area, near Jordan Creek. The final phase of instream habitat construction at this site was completed in 2020. Post-construction monitoring and adaptive management has been necessary each year since completion in order to address low flow conditions and potentially compromised fish passage in the project area. Staff from this project will collaborate with project managers from the Trout Unlimited contract (also contracted under 2002-029-00) to identify adaptive management opportunities at the Bonanza project site.

We will continue to work with the Yankee Fork Interdisciplinary (ID) Team in 2024-25. The team will conduct out-year planning and produce a prioritized list of projects for implementation through at least 2027. Contract staff have been working collaboratively with the Yankee Fork ID team to develop an Atlas planning and prioritization framework that incorporates fish and habitat data in the basin. This effort builds on past geomorphic assessments and basin planning documents (e.g., Yankee Fork Tributary Assessment [2010] and the 5-year strategy plan developed under a previous contract [Yankee Fork Habitat Restoration Plan, Yankee Fork Salmon River, Idaho, December 2019]) to help define the future direction of fish and habitat restoration in the Yankee Fork basin.